Method and assembly for determining instantaneous distance between a motor vehicle and a mobile electronic identification transmitter

Abstract

The invention relates to a method for determining the location of a mobile electronic identification transmitter for a motor vehicle (1) that can be unlocked by said identification transmitter, wherein an identification transmitter (2) is able to communicate by data transmission with the motor vehicle (1) via both a first wireless communication connection (3a) operating in accordance with the UWB standard and a second wireless communication connection (3b) operating in accordance with the BLE standard, the maximum communication distance of the first communication connection being smaller than the maximum communication distance of the second communication connection. The method comprises the steps of a) transmitting at least one signal (S), preferably continuously transmitting a plurality of signals (S), comprising a transmission time point of at least one signal (S) from the vehicle (1) to an identification transmitter (2) via a first communication connection (3a), a step b) causing the identification transmitter (2) to store the transmission time point and the reception time point of at least one signal (S) received by the identification transmitter (2), and a step c) transmitting a data packet (D) comprising the stored transmission times and reception times of the signals (S) transmitted in step a) from the identification transmitter (2) to the vehicle (1) via a second communication connection (3b).

Description

[Technical Field]

[0001] The present invention relates to a method for determining the instantaneous distance between a motor vehicle and a mobile electronic identification transmitter, and to an assembly comprising a motor vehicle and an identification transmitter configured / programmed to carry out this method. [Background technology]

[0002] Mobile electronic identification transmitters are used to allow access to a vehicle instead of a mechanical key. Communication between the identification transmitter and the vehicle is usually via a low-frequency radio system. This allows for the wireless transmission of authentication data, in particular for checking access rights. In this context, the use of radio connections according to the so-called UWB ("Ultra-Wide Band") standard is known. Using such a communication connection according to the UWB standard, not only is it possible to transmit authorization data between the identification transmitter and the vehicle, but such a UWB connection also makes it possible to determine the instantaneous distance (instantaneous distance, instantaneous distance, current distance) between the identification transmitter and the vehicle with a relatively high degree of accuracy.

[0003] For this purpose, common methods such as the so-called "polling" can be applied, which are based on determining the signal propagation time required for signal transmission from a signal transmitted from the identification transmitter to the vehicle or vice versa, and calculating the distance between the vehicle and the identification transmitter from this signal propagation time.

[0004] Such an authorization method, including distance determination, is described in DE 102017103187 A1.

[0005] In this case, it has been found to be a disadvantage that in order to determine the distance, data regarding the signal propagation time of the UWB signal must be transmitted from the identification transmitter to the vehicle, typically in the form of so-called timestamps characterizing the time of transmission and reception of each UWB signal.

[0006] However, transmitting all these timestamps over a UWB connection proves problematic due to the size of the resulting data packets, as regulatory restrictions on the "link budget" for data transmission often force a reduction in the transmission power from the identification transmitter to the vehicle, which can lead to an incomplete transmission of this data to the vehicle. Summary of the Invention [Problem to be solved by the invention]

[0007] It is therefore an object of the present invention to provide an improved method that takes into account the above-mentioned problems.

[0008] The above object is solved by the subject matter of the independent claims. Preferred embodiments are the subject matter of the dependent claims.

[0009] The basic idea of ​​the present invention is therefore to carry out, as known from conventional methods, measurements of the signal propagation time via a UWB connection between the vehicle and the identification transmitter for the above-mentioned authorization and distance determination, and to store the necessary points in time in time, also known to those skilled in the art as "timestamps", in the identification transmitter.

[0010] However, what is essential to the present invention is that in the method presented here, after the signal has been transmitted via the UWB connection for determining the propagation time, a data packet containing a timestamp is transmitted to the vehicle not via the UWB connection but via an additional BLE connection. Since such a BLE connection does not have the aforementioned limitations of the UWB connection in terms of link budget and transmission capacity, the timestamp can be reliably and completely transmitted from the identification transmitter to the vehicle, even in the form of a relatively large data packet, and can be evaluated there to determine the distance. In this way, the distance between the identification transmitter and the vehicle can be determined reliably and with high precision.

[0011] The method according to the invention is used to determine the distance of a mobile electronic identification transmitter to a vehicle that can be unlocked using this identification transmitter. The identification transmitter communicates with the vehicle by data transmission both via a first wireless communication connection operating in accordance with the UWB standard and via a second wireless communication connection operating in accordance with the BLE standard. Preferably, the maximum communication distance of the first communication connection is smaller than the maximum communication distance of the second communication connection.

[0012] The method according to the present invention comprises three steps a), b), and c). In step a), at least one signal containing the emission time of at least one such signal is transmitted from the vehicle to the identification transmitter via a first communication connection. Preferably, a plurality of such signals can be transmitted consecutively. In step b), the emission time and reception time of each signal or each of the plurality of signals received by the identification transmitter are stored in the identification transmitter. In step c), a data packet containing the stored emission and reception times of the signal or the plurality of signals transmitted in step a) is transmitted from the identification transmitter to the vehicle via a second communication connection. This information can then be used to calculate the distance between the identification transmitter and the vehicle at the time of signal transmission. This is essentially done by forming the difference between the reception time and the emission time. This difference corresponds to the time required for signal transmission. From this time, the distance of the identification transmitter relative to the vehicle at the time of signal transmission can be easily calculated.

[0013] According to a preferred embodiment, the method according to the invention comprises an additional means d) subsequent to means c), by which the instantaneous distance of the identification transmitter relative to the vehicle is determined from the data packet transmitted to the vehicle in means c), so that the method according to the invention can be used to determine the distance between the identification transmitter and the vehicle with very high accuracy.

[0014] Advantageously, a "polling" method can be used to implement measures a) and b). With such a polling method, signal propagation times of signals transmitted between the identification transmitter and the vehicle via the first communication connection can be easily determined. These signal propagation times can also be taken into account later to determine the distance between the identification transmitter and the vehicle.

[0015] To implement such a polling method, it is particularly practical for means b) to transmit a polling signal from the identification transmitter to the vehicle via the first communication connection. In response to this polling signal, the vehicle transmits at least one response signal, also via the first communication connection, to the identification transmitter, along with the time at which the response signal was emitted. The time at which the response signal was received can be stored by the identification transmitter. Thus, both times, i.e., the time at which the response signal was emitted and the time at which the response signal was received, can be added to the data packet transmitted to the vehicle. Thus, the data packet transmitted from the identification transmitter to the vehicle via the second communication connection includes the time at which the response signal was emitted and the time at which the response signal was received.

[0016] If only one reply signal is transmitted in response to a polling signal, the procedure is also known as the "ping-pong" method.

[0017] However, particularly preferably, in step b), two or more response signals are transmitted sequentially to the identification transmitter via the first communication connection in response to the polling signal. In this variant, the data packet transmitted from the identification transmitter to the vehicle via the second communication connection includes, for each response signal, the respective time of origination and the respective time of reception of the response signal. By transmitting two or more such response signals with their respective time stamps, the transmission time required for signal transmission from the identification transmitter to the vehicle can be determined particularly accurately. Therefore, the distance between the vehicle and the identification transmitter can also be calculated particularly accurately.

[0018] In an advantageous development of the method according to the present invention, the sending and receiving times of the polling signal can also be added to the data packet. In this way, the signal propagation time of the polling signal can also be taken into account for subsequent distance calculation. In this way, the accuracy with which the distance between the identification transmitter and the vehicle can be determined can be further improved.

[0019] The transmission of the data packets via the second communication connection carried out in point c) can in particular be carried out encrypted, so that safety-critical authorization data used to grant access to the vehicle can also be added to said data packets.

[0020] The invention further relates to an assembly comprising a motor vehicle and a mobile electronic identity transmitter capable of or in communication with the motor vehicle via a first wireless communication connection according to the UWB standard and a second wireless communication connection according to the BLE standard. To this end, the motor vehicle comprises a transceiver system for wireless data transmission via the two communication connections with the identification transmitters, the transceiver system being configured / programmed to carry out the method according to the invention. The above-mentioned advantages of the method according to the invention therefore also apply to the assembly according to the invention.

[0021] According to a preferred embodiment, the transceiver system comprises a first transceiver device for transmitting and receiving data via a first communication connection and a second transceiver device for transmitting and receiving data via a second communication connection, wherein the first transceiver device and the second transceiver device are data-transmissively connected to each other via a suitable, preferably wired, communication connection, whereby signal propagation times received by the second transceiver device can be transmitted to the first transceiver device for further processing.

[0022] According to a preferred embodiment, the electronic identification transmitter is part of or formed by a smartphone, which often already comes standard with a UWB and BLE standard-based transmitting and receiving unit.

[0023] Other important features and advantages of the invention emerge from the dependent claims, the drawings and the associated figure description taken together with the drawings.

[0024] It is to be understood that the features listed above, and those further described below, may not only be used in the combinations shown, but may also be used in other combinations or alone, without departing from the scope of the present invention. [Brief explanation of the drawings]

[0025] [Figure 1] FIG. 1 is a top view of an example of an assembly according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0026] Preferred embodiments of the present invention are illustrated in the drawings and will be described in detail in the following description, where like reference numbers indicate the same or similar or functionally identical parts.

[0027] FIG. 1 shows an example of an assembly 20 according to the invention in a top view. The assembly 20 comprises a motor vehicle 1 having a vehicle door 4, through which access to the interior space of the motor vehicle 1 is possible. The motor vehicle 1 comprises a transceiver system 10 for wireless data transmission, which is configured / programmed to execute the method according to the invention. The transceiver system 10 for wireless data transmission can be a control device connected to a field bus present in the motor vehicle 1, such as a LIN bus or a CAN bus. The assembly 20 further comprises a mobile electronic identification transmitter 2. The electronic identification transmitter 2 can be part of or formed by a smartphone 11. The identification transmitter 2 enables automatic authorization of access to the motor vehicle 1 during the process of approaching the motor vehicle 1. In particular, the vehicle door 4 can be unlocked after authorization has been granted.

[0028] The mobile electronic identity transmitter 2 can communicate with a transceiver system 10 of the motor vehicle 1 via a first wireless communication connection 3a according to the UWB standard and a second wireless communication connection 3b according to the BLE standard. For this purpose, the motor vehicle 1 can be provided with a first transceiver device 6a as part of the transceiver system 10, which can communicate via the first communication connection 3a by data transmission with a corresponding first transceiver device 7a provided in the identification transmitter 2. Correspondingly, the motor vehicle 1 can be provided with a second transceiver device 6b, which can communicate via the second communication connection 3b by data transmission with a corresponding second transceiver device 7b provided in the identification transmitter 2.

[0029] In this example, a first maximum communication distance of a first communication connection 3a from the vehicle 1 to the identification transmitter 2, measured from the vehicle 1, is smaller than a second maximum communication distance of a second communication connection 3b, also measured from the vehicle 1. The first transceiver 6a and the second transceiver 6b of the vehicle 1 can be connected to each other via a wired communication connection 8 so as to be able to transfer data therebetween.

[0030] The method according to the invention is explained below by way of example on the basis of FIG.

[0031] The method comprises three steps a), b) and c): In step a), a plurality of signals S, each containing an emission time point of the signal S, are transmitted successively from the vehicle 1 to the identification transmitter 2 via a first communication connection 3a.

[0032] According to the measure b), the time of each emission of the signals S received by the identification transmitter 2 and the time of reception of these signals S determined by the identification transmitter 2 are stored in the identification transmitter 2 .

[0033] A data packet D stored in means b) and containing the transmission and reception times of the signal S transmitted in means a) is transmitted in means c) from the identification transmitter 2 to the motor vehicle 1 via the second communication connection 3b.

[0034] To carry out steps a) and b), a so-called "polling" method can be applied. For this purpose, in step b), a polling signal PS is transmitted from the first transceiver 7a of the identification transmitter 2 via the first communication connection 3a to the first transceiver unit 6a of the motor vehicle 1. In response to this polling signal PS, the first transceiver unit 6a of the motor vehicle 1 transmits a number of response signals AS in succession to the first transceiver unit 7a of the identification transmitter 2, also via the first communication connection 3a, together with the origination timestamp of each response signal AS.

[0035] In this case, for each response signal AS the respective sending time and the respective receiving time of the response signal AS are added to the data packet D which is transmitted from the second transceiver unit 7b of the identification transmitter 2 via the second communication connection 3b to the second transceiver unit 6b of the motor vehicle 1. Thus, the data packet D transmitted from the identification transmitter 2 via the second communication connection 3b to the motor vehicle 1 contains the associated sending time and the associated receiving time for each generated response signal AS and also for each polling signal PS which triggers the response signal AS.

[0036] In an additional means d) following means c), the instantaneous distance of the identification transmitter 2 relative to the vehicle 1 is calculated from the data packet D transmitted to the vehicle 1 in means c) and comprising the time of origination and the time of reception. This calculation can be carried out in the first transceiver unit 6a. For this purpose, the data packet D received by the second transceiver unit 6b of the transceiver system 10 of the vehicle 1 can be transmitted via the wired communication connection 8 to the first transceiver 6a of the transceiver system 10, where it can be further processed to calculate the determined distance between the identification transmitter 2 and the vehicle 1.

[0037] The transmission of the data packet D over the second communication connection 3b carried out in means c) can be carried out in an encrypted form, so that the data packet D can also be accompanied by safety-critical authorization data used by the identification transmitter 2 to grant access to the vehicle 1. 。 [Prior art documents] [Patent documents]

[0038] [Patent Document 1] German Patent Application Publication No. 102017103187

Claims

1. 1. A method for determining the instantaneous distance between a mobile electronic identity transmitter (2) and a motor vehicle (1) that can be unlocked by said identification transmitter (2), said identification transmitter (2) being able to communicate by data transmission with said motor vehicle (1) via both a first wireless communication connection (3a) operating in accordance with the UWB standard and a second wireless communication connection (3b) operating in accordance with the BLE standard, the maximum communication distance of said first communication connection (3a) being smaller than the maximum communication distance of said second communication connection (3b), The method comprises: a) a first transmitting device (6a) for transmitting at least one signal (S) comprising the time point of emission of at least one signal (S) from the vehicle (1) to the identification transmitter (2) via the first communication connection (3a); b) means for storing in said identification transmitter (2) the time of emission and the time of reception at said identification transmitter (2) of said at least one signal (S) received by said identification transmitter (2); c) means for transmitting a data packet (D) containing the time of origination and the time of reception of the at least one signal (S) transmitted in the first transmitting device (6a) from the identification transmitter (2) via the second communication connection (3b) to a second receiving device (6b) of the motor vehicle (1); d) means for determining the instantaneous distance of the identification transmitter (2) relative to the vehicle (1) from the data packet (D) transmitted to the second receiving device (6b) in means c); It encompasses The first transmitting device (6a) and the second receiving device (6b) are connected to each other via a wired communication connection (8) so that data can be transmitted. A method characterized by:

2. In the first transmitting device (6a), a plurality of signals (AS) including the transmission time point of at least one signal (S) are continuously transmitted.

2. The method of claim 1 .

3. A polling method is applied to execute the first transmitting device (6a) and the means b).

3. The method according to claim 1 or 2.

4. In the means b), a polling signal (PS) is transmitted from the identification transmitter (2) to the vehicle (1) via the first communication connection (3a); In response to said polling signal (PS), at least one response signal (AS) comprising a time point of the response signal (AS) is transmitted from said motor vehicle (1) to said identification transmitter (2) via said first communication connection (3a), The time of sending the response signal (AS) at the identification transmitter (2) and the time of receiving the response signal (AS) are added to the data packet (D) transmitted from the identification transmitter (2) via the second communication connection (3b) to the vehicle (1).

3. The method according to claim 1 or 2.

5. In the means b), two or more response signals (AS) are transmitted sequentially to the identification transmitter (2) via the first communication connection (3a) in response to the polling signal (PS), The data packets transmitted from the identification transmitter (2) to the motor vehicle (1) via the second communication connection (3b) are appended with the respective sending time and respective receiving time of each received response signal (AS).

5. The method according to claim 4.

6. The sending and receiving times of the polling signal (PS) are also added to the data packet (D).

5. The method according to claim 4.

7. The transmission of the data packet (D) performed in the means c) is carried out in an encrypted form.

3. The method according to claim 1 or 2.

8. a motor vehicle (1) including a transmitting / receiving system (10) for wireless data transmission (10) configured / programmed to carry out the method according to claim 1 or 2; a mobile electronic identity transmitter (2) capable of communicating with or in communication with the transmitting / receiving system (10) of the motor vehicle (1) via a first wireless communication connection (3a) according to the UWB standard and a second wireless communication connection (3b) according to the BLE standard; have An assembly (20).

9. The first transmitting device (6a) is a first transmitting / receiving device (6a) for transmitting and receiving data via the first communication connection (3a), the second receiving device (6b) is a second transmitting / receiving device (6b) for transmitting and receiving data via the second communication connection (3b); The transmitting / receiving system (10) includes the first transmitting / receiving device (6a) and the second transmitting / receiving device (6b), The first transceiver (6a) and the second transceiver (6b) are connected to each other via a wired communication connection (8) so that data packets (D) received by the second transceiver (6b) of the transceiver system (10) can be transmitted to the first transceiver (6a) for further processing.

9. The assembly according to claim 8, characterized in that

10. The electronic identification transmitter (2) is part of or formed by a smartphone (11).

10. The assembly according to claim 9, characterized in that

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